.main-block {
  background-color: rgb(207, 206, 206);
  height: 700px;
  overflow: auto;
  border: 1px solid black;
  border-top-left-radius: 30px;
  border-bottom-left-radius: 30px;
}

.card {
  background-color: rgb(233, 190, 139);
  width: 300px;
  height: 250px;
  border: 1px solid black;
  border-radius: 20px;
  box-sizing: border-box;
  padding: 20px 20px 30px;
  box-shadow: inset 0 0 10px black;
  margin: 8px 10px 15px 3px;
  display: inline-block;
}

.secret {
  margin: 50px 657px;
  border-radius: 50%;
  box-shadow: 0 0 20px purple;
}